Fluid hoist



5 Sheets-Sheet l FLUID HOIST J. F. HEIL ET AL Filed July l.

Aug. 18, 1931.

Aug- 18, 1931- J. F. HEM. ET AL 1,819,167

FLUID HOIST Filed July 1. 1929 5 Sheets-Sheet 2 INVENToRs J5 v BY al 5. 4a/Zu,

FLUID HoIsT Filed July 1,

1929 5 Sheets-Sheet 3 A TTOKYEYS Aug. 18, 1931. J. F. HEM. E'rAL FLUID HOIST Filed July 1. 1929 5 sheets-sheet 4 1&9@ /f/ Y v f T- 1 2 |fz j@ f3- uw l A TTORNEYJ' Aug. 18, 1931. J. F. HEM. ET AL FLUID HOIST Filed July l.

1929 5 Sheets-Sheet 5 Z Il 5 4 W f INVENTOR.: 1 o? M f BY 9AM/bt,

V 4 Patented Aug. 18, 1931 PATENT r OFFICE JOSEPH E. HEIIJ, E MILWAUKEE, AND

ASSIGNORS TO THE HEIL CO., OF MILWAUKEE,

WISCONSIN EARL B. GRUBER, 0F WAUWATOSA, WISCONSIN,

WISCONSIN, A CORPORATION OF FLUID HOIST Application led July 1, 1929. Serial No. 375,127.

This invention relates to improvements in Huid hoist, more particularly adapted for use on small trucks having dumping bodies.

It is one of the objects of the present in- 5 vention to provide a fluid hoist, suitable for the purpose desired, which is of such compact size and shape as to permit its use in restricted spaces beneath the bodies of the smaller trucks. p

A further object of the invention is to provide a fluid hoist in which the actuating pump is positioned on one side of the hoist cylinder and the controlling valve is placed on the other' side of said cylinder to simplify l' the connections and conduits.

A further object of the invention is to provide a luid hoist which, while preferably used as a one cylinder hoist, may also be used as a two cylinder hoist.

A further object of the invention is to provide a fluid hoist in which the movement of the piston will automatically stop when the piston reaches the end of its stroke.

A further object of the invention is to provide a luid hoist having means for bypassing the fluid from one side of the piston to the other to permit the piston to initi-h ally move downwardly.

A further object Iof the inyention is to provide a iluid hoist having an oil reservoir formed in theupper portion of the cylinder to receive and hold surplus oil and oil displaced by the piston rod when the piston is in its lower position.

A lfurther object of the invention is to provide a fluid hoist in which the piston rod is so connected to the truckL body as to exert the maximum lifting force with the minimum application of power. K

A further object of the invention is to provide a fluid hoist having a gear pump for forcing the fluid from one side of the piston to the other.

A further lobject of the invention is to provide a fluid hoist which is of simple con! struction is strong and durable and :is well adapted for the purpose described.

With the above and other objects in view, the invention consists of the improved fluid hoist and its parts and combinations as set forth in the claims, and all equivalents thereof.

'I'n the accompanying drawings, in which the same reference characters indicate the same parts in all of the views:

Fig. l is a side view of a motor truck provided with the improved luid hoist, parts broken away to show other parts in the rear thereof; the view also illustrating, by dotted lines, the body portion of the truck in its upper position;

Fig. 2 is a central, vertical, sectional view of the hoist and portions of the truck taken on a largerscale;

Fig, 3 is a transverse sectional view taken on line 3-'3 of Fig. 2;

Fig. 4 is a horizontal sectional View taken on line 4.-4 of Fig. 2; K

Fig. 5 is a horizontal sectional view taken on line 5-5 ofpFig. 2;

yFig. 6 is a vertical sectional view taken on line 6 64 of Fig. 2;

Fig. 7 is a front view of a modilied form of hoist having two cylinders, the chassis and body parts of the truck being shown in section Fig.J 8 is a central vertical sectional view of the parts shown in Fig. 7, other parts being broken away to show interior construction;

Fig. 9 is asectional detail view of one of the cylinders; ,f

Fig. 10 is a sectional detail "view taken on line 10-10 of Fig. 9;

Fig. 11'is a horizontal sectional detail view taken on line 111-11 of Fig. 9; and

Fig. 12 is a horizontal sectional detail view -taken on line 12-12 of Fig. 9.

Referring to the drawings, the numeral 8 indicates a portion of a motor truck, 9 the side members of the chassis or frame, 10the cab or seat portion and 11 the tiltable load carrying body of the truck. I Said body, near its rear end portion, is pivotally connected to the opposite side members 9 by pivot or ulcrum brackets 12 and 13.

The improved fluid hoist 14 comprises, in oneexemplication of the invention, a cylinder 15 having lower opposite, outwardly projecting portions 1'6 provided with alined trunnion recesses 17 for receiving the inwardly projecting trunnions 18 of the trunnion brackets 19 which engage the side portions of and rest upon the upper edges of spaced longitudinal extending channels or sills-9 mounted on a'nd forming parts of the truck chassis. The trunnion brackets are bolted to said channels. The cylinder 15 is pivotally supported on said trunnions and extends upwardly therefrom and is provided with a piston 20 reciprocally positioned therein. A piston rod 21, connected to the piston, extends upwardly throughthe upper closed end or head 14 and the stuffing nut 22 thereof, and is provided with an upper eyed end 23. Said eyed end is pivotally connected to the bottom portion by a transverse pivot rod 24 which isI mounted in brackets 25 connected to side members 11 of the body 11. Said pivotal connections permit the piston rodl and cylinder to tilt and aline with said pivotal connections while the 'truck body is traveling its arc of movement to unloading position.

The cylinder is formed with a lower port 26 and an upper port 27 which respectively charge or discharge the fiuid medium below or above the piston. The port 26 is in communication with a duct 28 which is formed in the'front side wall of the cylinder and leads upwardly therefrom and connects to a forwardly extending duct 29 having a spring pressed ball check valve 30. rlhe upper port 27 is on a plane lower than the upper portion of the piston when in its upper position, so that said port is closed when the piston is in its upper position. Said port 27 is also in communication, by means of an annular duct 31, with an upper forwardly extending pump supply duct 32 above the duct 29.

` rotary gear pump 33 is mounted on the front portion of the cylinder to connect the ducts 29 and 32 respectively, below and above the pump gears as shown in Figs. 2 and 6. The ball valve 30 opens outwardly `from the pump.

One of the gears of the pump is connected to and driven by the transmlssion 34 by al connecting rod or shaft 35. .A sliding connection 36 and universal joints 37 form parts of the rod -or sha-ft 35 to permit tilting of the i`cylinder. The transmission of power to the `'pump shaft is controlled by a controlling rod 34 and a lever 36.

A by-pass port 38 connects with the lower portion of the bore of the cylinder and also to a by-pass duct 39 which is formed in the rear side wall of the cylinder and connects with the duct 40 of a valve casing 41 mounted on the rear portion of the cylinder 15. A plug valve 42 is positioned within the valve casing and is provided with an angular port 4.3, and the valve may be turned to register said port with the duct 40 and a by-pass duct 44 in `communication with the bore of the upper portion of the cylinder, as shown in Figs. 2 and 5. The valve is turned to register its port with by-pass ports 4() and 44 when it is desired to lower the truck body.

'lhe vvalve arm 45 is connected to one arm of a bell crank lever 46 by an adjustable link 47, and the other arm of the bell crank lever is connected to a rod 48. A lever 49 within the cab is connected to the 'rod 48 and controls the opening and closing of the valve 42.

)As considerable more space within the cylinder is required to accommodate the piston rod when it is in its inner or lower position than when in its outer or upper position, and to supply the varying amounts,xthe upper portion of the cylinder is formed with an integral chamber 50 which comprises an enlargement of the cylinder and is preferably but necessarily closed off from the piston bore by an extension head 51 which forms an inwardly extending portion of the cylinder head 14. The chamber 50 is in communication with the bore 44, the valve port 43, the duct 39 and the port 38 below the piston when the valve is in open position, as shown in Fig. 2. y

When the piston is almost in its upper position it will cover the port 27, and to permit slight further upward movement and also initial downward movement of the piston, the extension head has opposite side edge openings 27 extending therethrough, which permit the fiow of fluid therethrough. As thus formed the surplus fluidfmedium within the chamber 50 can pass downwardly through the head extension openin s to the cylinder bore and ducts of the cy inder to permit the piston to reciprocate. The head 14 of the cylinder is provided with an upwardly extending ball check valve 152, which is normally in open position to permit the escape of air from the chamber 50 when the fiuid medium is flowing into the chamber 50. When the piston is in its upper position 1t covers the port 27 as before mentioned, so that to permit the initial downward movement of the piston, the ducts or openings 27, before mentioned, are provided to permit the fiuid medium beneath the piston to fiow upward into the chamber 50 and above the piston until the piston uncovers the port 27, and when so uncovered, the fluid will fiow therethrough and above the piston and 4into the chamber 50.

The pivot brackets 12 are located intermediate the ends of the body, but closer to the rear portion of the body than to the front. The fluid hoist is pivotally connected to the body adjacent the rear axle of the truck and comparatively a considerable distance above the plane of the pivot brackets 12. This construction and the positioning of the cylinder pivot support adjacent 12 inclusive, the construction is substantially the lower end of the cylinder permits the use of a very short cylinder and movement of the piston to tilt the dump body with the minimum amount of power. Particular attention is directed to the fact that the iiuid hoist including hinged together frame parts are all assembled together as a unit which can be easily interposed between the chassis and the body of a truck and connected thereto to form a power driven dump body. Furthermore, attention is also directed to the fact that the pivotal connections of all of the parts are arranged so that they will be positioned to the rear of the rear axle of the truck upon which the frame is mounted.

In use of the form thus far described,

'the iuid hoist is mounted on a motor truck in the manner shown in Fig. 1, and when it is desired to dump the contents of the truck body, the transmission controlling rod is operated to transmit motion to the pump, and the operation of the pump will draw the Huid medium from above the piston and force it into the cylinder below the piston, and thus raise said piston. The upward 4movement of the piston will tilt the truck body connected thereto, and when the piston has closed the upper port 27, and thus automatically closed the major portion ofvits supply of fluid medium to the pump, the pump may continue to operate, but as its supply of fluid medium is substantially cut off and it cannot pump any more into the cylinder below the piston, therefore the further upward movement of the piston will automatically stop. The head extension 5l will also positively stop further upward movement of the piston. yThis feature is very desirable, as it eliminates any danger of damage to the hoist in the event that the operator inadvertently neglects to stop the operation of the pump.

The piston will. remain in its upper position whether or not the pump is in operation.

If it is now desired to lower the truck body, the valve rod 48 is operated to open the valve 42, and when opened as shown in Fig. 2, the fluid medium in the cylinder below the piston will flow upwardly through the ducts 39, 40, valve 42 and duct 44 and into the cylinder above the piston, until the piston moves downwardly to the lower end of the cylinder, the speed of movement being controlled by the opening in the valve. When the piston is in its lower position, the

' excess fluid medium forced out of the cylinder bore by the piston rod will ill the space in the chamber 50 after it has filled the bore of the cylinder above the piston.

In the modified form shown 1n Figs. 7 to the same, with the exception that two cylinders and connected parts are used instead of one as in the rst form described, and

the pump and the valve are placed between the cylinders, and the ducts extend to both cylinders. In view of this similarity of parts, the same reference numerals will be used inreferring to the parts similar to the first form. The cylinders 15 are spaced apart to position the pump 33 and the valve casing 4l therebetween. The ball valve 30 in this form is in communication with the upper port of the pump, and the ducts 28 and 28 connect the lower end portions of the cylinders to the ball valve duct. The `lower port 32 of the pump is connected to the upper end portions of the cylinders by ducts 52 and 27. The duct 52 is also connected to the storage chambers 50 by means of ducts 53, so that when the pump is rotated the Huid medium is drawn from the upper portions of the cylinders above the pistons through the ducts 52 and 32 to the pump, and from the pump the fluid medium is forced by the ball check valve and through the ducts 29', 28 and 28 to the lower ends of the cylinders below the pistons, and will force said pistons upwardly.

The valve 42 is the same as the valve in the main form, and is connected to the ducts 28 and 52 to by-pass the pump by means of the ducts 44 and 40, so that when it is desired to lower the dump body the valve 42 is turned to open communication between the ducts 44 and 40 and permit the weight of the truck body to cause the fluid medium to flow from beneath the pistons into the cylinders above the pistons.

In either form described, the speed of lowering the body is controlled by the opening or closing, more o r less, of the port of the valve, and the speed of dumping may be controlled by the speed at which the truck transmission is run.

From the foregoing description it will be seen that the Huid hoist is' of simple construction, and that the pivotal connection of the lower portion of the cylinder with the truck, and the positioning of the cylinder adjacent the pivotal connection of the dump body with the truck chassis, permits the use of a short cylinder and a considerable clearance between the lower end of the cylinder and the ground.

What we claim as our invention is:v

1. The combination with atruck having a dump body portion pvotally connected thereto at points intermediate the ends of the body, but closer to the rear end portion of the body, of a Huid hoist therefor, comprising a'cylinder pivotally connected adjacent its lower end to the truck, said cylinder having a piston in its bore and a piston rod which extends upwardly and is lpivotally connected at its upper end to a medial portion of the bodyv to tilt the front portion of the body upwardly, said cylinder `also having an upper head and a spaced partition carried by said head and forming a storage chamber in the upper portion of the cylinder, the piston rod reciprocally extending through the partition and the head, and

the cylinder having upper and lower ports opening into the bore of the cylinder, an outer duct connecting the upper andlower ports together, a pump intersecting the outer duct for moving a Huid medium within the cylinder from one side of the piston to the other,`ducts by-passing the pump, a valve controlling the iiow of fluid medium through the by-pass ducts, and a duct connecting the bore of the cylinder to the storage chamber. 2. Thev combination with a truck having a -dump body pivotally connected thereto, of a fluid hoist therefor comprising, a cylinder pivotally connected adjacent its-lower end to the truck, said cylinder having a piston in lits bore and a piston rod which extends upwardly and is pivotally connected at its upper end to the body to tilt the latter, said cylinder also having a removable upper head and a spaced partition formed integral with said head and cooperating with said cylinder to provide a storage chamber in the upper portion of the cylinder, said piston rod reclprocally extending through said partition and head and said cylinder having upperand lower ports opening into the cylinder bore, a pump intersecting said ports for moving a Huid medium from one side of said piston .to the other, and means for permitting passage of iiuid from one side of said pls-ton to the other without passing through said pump. D 3. The combination with a truck having a dump body pivotally connected thereto, of a fluid hoist therefor comprising, a cylinder pivotally connectedto the truck, said cylinder having a piston in its bore and a piston Arod extending upwardly and pivotally l connected at its upper end to the body to tilt the latter, said cylinder having an upper removable head and a spaced partition formed integral therewith and cooperating with said cylinder to form a storage chamber in the upper portion ofA said cylinder, said piston rod being reciprocable through said partition and head and said cylinder havingupper and lower ports opening into the bore thereof above and beneath said partition, a pump for moving fluid medium from one side of said piston to the other through said ports, and a valve controlled by-pass rfor permitting the How of iiuid medium from one side of said piston'to the other without passing through said pump. i

In testimony whereof, we afix our signatures.

JOSEPH F. HEIL. EARL B. GRUBER. 

